A battery is a commonly used source for supplying electrical power. A battery may store electrical power as electrical charge, or may produce electrical power through a chemical reaction. Some batteries are single-use, where upon use, the battery has to be replaced. Other batteries are reusable. The reusable batteries discharge when connected to a load circuit, and recharge when connected to a charging circuit.
A battery comprises one or more cells, each of which can hold an amount of the electrical charge or perform a portion of the chemical reaction. A cell in a battery produces a voltage, or potential difference, and supplies current to a load. A load is an electrical circuit including an electrical component with impedance.
More than one cell can be electrically connected to one another with a conductive material in a configuration to increase an output of the configuration. For example, when several cells are connected in series, the configuration produces a higher voltage than a single cell. As another example, when several cells are connected in parallel, the configuration produces a higher current than a single cell.